A heat cycle resistant composite electrode for a perovskite photovoltaic module for space and a method of manufacturing the same

Abstract

The application belongs to the technical field of photovoltaic devices, and discloses a heat cycle resistant composite electrode for a perovskite photovoltaic module for space use and a preparation method thereof. The heat cycle resistant composite electrode is used for being arranged at an electrode lead-out area of a metal electrode of a perovskite photovoltaic module. The heat cycle resistant composite electrode comprises a composite electrode body, a curved flexible conductive adhesive layer and a single-sided Cu conductive adhesive tape. The composite electrode body is arranged at the electrode lead-out area. The curved flexible conductive adhesive layer is arranged on the composite electrode body and extends in a curved shape along the surface of the composite electrode body. The single-sided Cu conductive adhesive tape is arranged on the curved flexible conductive adhesive layer and is electrically connected with the composite electrode body through the curved flexible conductive adhesive layer. The problems of interface warping, local peeling, micro-crack propagation, contact resistance increase and even electrode lead-out failure in a space heat cycle environment are solved.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic device technology, and particularly relates to a thermally resistant composite electrode for a space perovskite photovoltaic module and its preparation method. Background Technology

[0002] Perovskite photovoltaic (PV) modules possess advantages such as high photoelectric conversion efficiency, tunable material systems, low fabrication temperatures, small mass per unit area, and great flexibility, making them a key candidate technology for spacecraft, satellite platforms, near-space vehicles, and space power systems. Compared to traditional crystalline silicon solar cells and some III-V group space solar cells, perovskite PV modules show promising application prospects in terms of lightweight design, high specific power, large-area fabrication, and flexible deployment, thus attracting increasing attention in the space photovoltaic field.

[0003] Existing perovskite photovoltaic (PV) modules mostly employ conventional electrical connection processes used in terrestrial or thin-film PV modules for electrode lead-out. For example, after forming metal electrodes above the perovskite power generation layer, the positive and negative currents are led out using methods such as single-sided Cu conductive tape, metal foil, solder ribbon, conductive adhesive, or low-temperature solder. This type of solution can meet basic conductive connection requirements in conventional terrestrial environments and has advantages such as simple process, low cost, and convenient connection. However, it is primarily designed for terrestrial temperature and humidity and conventional mechanical load conditions, and has not fully considered the impact of long-term thermal cycling, high vacuum, ultraviolet radiation, and particle radiation on the interface reliability of the electrode lead-out area in space environments.

[0004] In space environments, perovskite photovoltaic modules need to withstand drastic temperature fluctuations over long periods. The difference in thermal expansion coefficients between different materials can easily generate periodic tensile, shear, and peeling stresses in the electrode lead-out areas. In particular, the mismatch in thermal expansion coefficients between the single-sided Cu conductive tape, metal electrodes, perovskite power generation layer, ITO electrodes, and glass or flexible resin substrate can easily lead to stress concentrations at the edges of metal electrodes, adhesive layer boundaries, or functional layer interfaces. This can result in interface warping, localized peeling, microcrack propagation, and increased contact resistance, and in severe cases, failure of positive and negative electrode current extraction or module open circuit. Summary of the Invention

[0005] To address the problem that existing perovskite photovoltaic modules for space use often employ single-sided Cu conductive tape, metal foil, conductive adhesive, or low-temperature solder for direct connection in the electrode lead-out area, which is prone to interface warping, localized peeling, microcrack propagation, increased contact resistance, and even electrode lead-out failure due to the large differences in thermal expansion coefficients between the metal electrode, perovskite power generation layer, ITO electrode, glass substrate, or flexible resin substrate under space thermal cycling conditions, this invention provides a thermal cycling resistant composite electrode for space-use perovskite photovoltaic modules and its preparation method.

[0006] The present invention solves the above-mentioned technical problems through the following technical means: In a first aspect, the present invention provides a thermally resistant composite electrode for a space perovskite photovoltaic module. The thermally resistant composite electrode is used to be disposed in the electrode lead-out area of ​​the metal electrode of the perovskite photovoltaic module. The thermally resistant composite electrode includes a composite electrode body, a curved flexible conductive adhesive layer, and a single-sided Cu conductive tape. The composite electrode body is disposed in the electrode lead-out area; The curved flexible conductive adhesive layer is disposed on the composite electrode body and extends in a curved shape along the surface of the composite electrode body; The single-sided Cu conductive tape is disposed on the curved flexible conductive adhesive layer and is electrically connected to the composite electrode body through the curved flexible conductive adhesive layer; The composite electrode body is a multilayer nano-metal composite electrode or a conductive adhesive composite layer.

[0007] Preferably, the extension trajectory of the curved flexible conductive adhesive layer is S-shaped, serpentine, wavy, arc-shaped, zigzag-shaped, or a combination thereof.

[0008] Preferably, the multilayer nano-metal composite electrode comprises a flexible resin transition layer, an intermediate porous stress-buffered silver layer, and a surface dense conductive silver layer, which are sequentially stacked along the direction away from the perovskite power generation layer.

[0009] Preferably, the flexible resin transition substrate is a PI layer, a PET layer, a PEN layer, a PC layer, a flexible epoxy resin layer, a polyurethane resin layer, or an acrylate resin layer.

[0010] Preferably, the intermediate porous stress-buffered silver layer is a porous silver layer or a porous composite metal layer with silver as the main component; the surface dense conductive silver layer is a dense silver layer or a dense composite conductive layer with silver as the main component.

[0011] Preferably, the intermediate porous stress-buffered silver layer is in the form of islands, columns, loose granules, or a porous continuous network, the thickness of the intermediate porous stress-buffered silver layer is 50nm to 1000nm, and the thickness of the surface dense conductive silver layer is 100nm to 3000nm.

[0012] Preferably, the conductive adhesive composite layer includes a perovskite-side low-modulus flexible adhesive layer, a conductive skeleton intermediate layer, and an encapsulation-side buffer surface layer, arranged sequentially along the direction away from the perovskite power generation layer.

[0013] Preferably, the perovskite-side low-modulus flexible adhesive layer is a silicone-based, polyurethane-based, flexible epoxy-based, or acrylate-based adhesive layer; the conductive framework intermediate layer includes silver particles, silver nanowires, silver flakes, copper particles, carbon nanotubes, graphene, or combinations thereof; and the encapsulation-side buffer surface layer is an epoxy resin layer, a polyurethane layer, a fluorosilicone resin layer, an acrylate resin layer, or combinations thereof.

[0014] Secondly, the present invention provides a method for preparing a thermally cycling resistant composite electrode for a space perovskite photovoltaic module, comprising the following steps: S1. A composite electrode body is formed in the electrode lead-out area of ​​the metal electrode of the perovskite photovoltaic module; S2. A curved flexible conductive adhesive layer is formed on the composite electrode body; S3. Apply a single-sided Cu conductive tape to the curved flexible conductive adhesive layer, so that the single-sided Cu conductive tape is electrically connected to the composite electrode body through the curved flexible conductive adhesive layer to obtain a thermally resistant composite electrode.

[0015] Preferably, in step S1, when the composite electrode body is a multilayer nano-metal composite electrode, the following steps are included: S11. A flexible resin transition substrate is formed in the electrode lead-out area; S12. Deposit an intermediate porous stress-buffered silver layer on the flexible resin transition substrate; S13. Deposit a dense conductive silver layer on the surface of the intermediate porous stress buffer silver layer. The intermediate porous stress-buffered silver layer is formed by physical vapor deposition, with a deposition pressure of 1.0 Pa to 5.0 Pa, a deposition power of 20 W to 80 W, and a deposition temperature not exceeding 80 °C; the surface dense conductive silver layer is formed by physical vapor deposition, with a deposition pressure of 0.1 Pa to 0.8 Pa, a deposition power of 80 W to 200 W, and a deposition temperature of room temperature to 120 °C. When the composite electrode body is a conductive adhesive composite layer, step S1 includes the following steps: forming a perovskite-side low-modulus flexible adhesive layer, a conductive skeleton intermediate layer, and an encapsulation-side buffer surface layer sequentially in the electrode lead-out area.

[0016] The beneficial effects of this invention are: 1. The present invention sets a composite electrode body in the electrode lead-out area of ​​the metal electrode of the perovskite photovoltaic module, and connects it with a single-sided Cu conductive tape through a curved flexible conductive adhesive layer. This transforms the traditional connection method of directly attaching the single-sided Cu conductive tape to the metal electrode into a hierarchical connection method of "composite electrode body - curved flexible conductive adhesive layer - single-sided Cu conductive tape", which is beneficial to improve the interface stress distribution in the electrode lead-out area.

[0017] 2. When the composite electrode body adopts a multilayer nano-metal composite electrode, a hierarchical structure is formed by a flexible resin transition layer, an intermediate porous stress-buffered silver layer, and a surface dense conductive silver layer, from the flexible transition layer to the porous buffer layer and finally to the dense conductive layer. The flexible resin transition layer improves the interface compatibility with the metal electrode or electrode lead-out area of ​​the perovskite component; the intermediate porous stress-buffered silver layer provides a certain deformation space through its porous or island-like structure; and the surface dense conductive silver layer ensures the continuity and conductivity stability of the current lead-out path.

[0018] 3. When the composite electrode body adopts a conductive adhesive composite layer, the perovskite-side low-modulus flexible adhesive layer, the conductive skeleton intermediate layer, and the encapsulation-side buffer surface layer can respectively undertake the functions of flexible bonding, conductive transmission, and external buffer protection, so that the conductive adhesive composite layer has the functions of interface bonding, conductive connection, and thermal cycling buffer.

[0019] 4. The curved flexible conductive adhesive layer of the present invention extends in a curved shape. Compared with the traditional straight connection path, it can provide geometric deformation redundancy in the electrode lead-out area, so that the local strain can be dispersed through the curved path during thermal expansion and contraction or bending, thereby reducing stress concentration. Attached Figure Description

[0020] Figure 1 This is an overview of the positive and negative electrode lead-out locations, structures, and replacement locations of perovskite modules.

[0021] Figure 2 The metal electrodes are replaced with a flexible conductive adhesive + multilayer metal composite structure.

[0022] Figure 3 This is a structural diagram of the perovskite component after the composite electrode has been replaced.

[0023] Figure 4 This is a schematic diagram of the curve trajectory of the "flexible conductive adhesive + multilayer composite electrode structure".

[0024] Wherein, 1 is the glass substrate; 2 is the ITO electrode; 3 is the perovskite power generation layer; and 4 is the metal electrode. 5 is the composite electrode body; 51 is the multilayer nano-metal composite electrode; 511 is the flexible resin transition bottom layer; 512 is the intermediate porous stress buffer silver layer; 513 is the surface dense conductive silver layer; 52 is the conductive adhesive composite layer; 521 is the perovskite side low modulus flexible adhesive layer; 522 is the conductive framework intermediate layer; 523 is the encapsulation side buffer surface layer.

[0025] 6 is a curved flexible conductive adhesive layer; 7 is a single-sided Cu conductive tape; Detailed Implementation The present invention will be further described below with reference to specific embodiments. It should be understood that the following embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent substitutions or conventional adjustments made to the composite electrode layer system, the trajectory of the curved flexible conductive adhesive layer, the deposition process parameters, the conductive adhesive system, or the perovskite component substrate form based on the concept of the present invention should be included within the scope of protection of the present invention.

[0026] like Figures 2 to 3 As shown, this invention provides a thermally resistant composite electrode for a space-use perovskite photovoltaic module and its fabrication method. The perovskite photovoltaic module includes, from bottom to top, a glass substrate 1, an ITO electrode 2, a perovskite power generation layer 3, and a metal electrode 4. The metal electrode 4 has an electrode lead-out region for leading out positive or negative current. The thermally resistant composite electrode is disposed in the electrode lead-out region of the metal electrode 4 and is electrically connected to a single-sided Cu conductive tape 7.

[0027] In this invention, the thermal cycling resistant composite electrode includes a composite electrode body 5, a curved flexible conductive adhesive layer 6, and a single-sided Cu conductive tape 7. The composite electrode body 5 is disposed on the electrode lead-out area of ​​the metal electrode 4; the curved flexible conductive adhesive layer 6 is disposed on the composite electrode body 5 and extends in a curved shape along the surface of the composite electrode body 5; the single-sided Cu conductive tape 7 is disposed on the curved flexible conductive adhesive layer 6 and is electrically connected to the composite electrode body 5 through the curved flexible conductive adhesive layer 6.

[0028] The extension trajectory of the curved flexible conductive adhesive layer 6 can be S-shaped, serpentine, corrugated, arc-shaped, zigzag-shaped, or a combination thereof. Preferably, the curved flexible conductive adhesive layer 6 is an S-shaped flexible conductive adhesive layer. Through the curved trajectory design, the conductive adhesive lines have deformation redundancy in the length direction. Under the action of thermal expansion and contraction, component bending, or assembly stress, local stress can be dispersed through peaks, troughs, or arc segments, reducing stress concentration at both ends of the straight conductive adhesive.

[0029] The composite electrode body 5 can adopt two structural forms. The first structural form is a multilayer nano-metal composite electrode 51, and the second structural form is a conductive adhesive composite layer 52. Both structural forms can form a layer transition connection from the perovskite device layer to the external single-sided Cu conductive tape 7 in the electrode lead-out area of ​​the metal electrode 4 of the perovskite photovoltaic module. This improves the problems of interface peeling, warping, crack propagation, or electrical connection failure caused by the large difference in thermal expansion coefficient when the traditional single-sided Cu conductive tape is directly attached to the metal electrode 4.

[0030] Example 1. Multilayer nano-metal composite electrode type thermal cycling resistant composite electrode This embodiment provides a thermally resistant composite electrode that uses a multilayer nano-metal composite electrode as the composite electrode body 5.

[0031] like Figure 2 As shown, the perovskite photovoltaic module includes, from bottom to top, a glass substrate 1, an ITO electrode 2, a perovskite power-generating layer 3, and a metal electrode 4. The metal electrode 4 has an electrode lead-out area. The thermally resistant composite electrode is disposed in the electrode lead-out area of ​​the metal electrode 4.

[0032] In this embodiment, the composite electrode body 5 is a multilayer nano-metal composite electrode 51. The multilayer nano-metal composite electrode includes a flexible resin transition bottom layer 511, an intermediate porous stress buffer silver layer 512, and a surface dense conductive silver layer 513, which are sequentially stacked along the direction away from the perovskite power generation layer 3.

[0033] The flexible resin transition substrate 511 is disposed in the electrode lead-out area of ​​the metal electrode 4. The flexible resin transition substrate 511 serves to form a flexible transition interface between the metal electrode 4 and the upper silver-based conductive structure. The flexible resin transition substrate 511 can be a PI layer, a PET layer, a PEN layer, a PC layer, a flexible epoxy resin layer, a polyurethane resin layer, or an acrylate resin layer. Preferably, the flexible resin transition substrate 511 is a flexible epoxy resin layer or a polyurethane resin layer. The thickness of the flexible resin transition substrate 511 can be 0.5 μm to 20 μm, preferably 1 μm to 10 μm.

[0034] The intermediate porous stress-buffered silver layer 512 is disposed on the flexible resin transition substrate 511. The intermediate porous stress-buffered silver layer 512 is a porous silver layer or a porous composite metal layer with silver as the main component, and its microstructure is island-like, columnar, loosely granular, or a porous continuous network. The thickness of the intermediate porous stress-buffered silver layer 512 is 50 nm to 1000 nm, preferably 100 nm to 500 nm. This layer forms a micro-deformation space through its porous or island-like structure, absorbing the difference in thermal expansion and contraction between the upper and lower layers during spatial thermal cycling, reducing the direct transfer of thermal stress to the interface between the perovskite power generation layer 3 and the transmission layer.

[0035] The dense conductive silver layer 513 is disposed on the intermediate porous stress-buffered silver layer 512. The dense conductive silver layer 513 is a dense silver layer or a dense composite conductive layer with silver as the main component. The thickness of the dense conductive silver layer 513 is 100nm to 3000nm, preferably 300nm to 1500nm. This layer forms a continuous conductive film to ensure the conductivity continuity of the current lead-out path and to form a stable electrical connection with the curved flexible conductive adhesive layer 6.

[0036] The preparation method of this embodiment includes the following steps: S1. Perform surface pretreatment on the electrode lead-out area of ​​the metal electrode 4 of the perovskite photovoltaic module. The surface pretreatment includes solvent cleaning, ultraviolet ozone treatment, ion cleaning, plasma activation, or a combination thereof. Preferably, the electrode lead-out area is first cleaned with anhydrous ethanol or isopropanol, and then plasma activation is performed for 30s to 300s to remove surface contaminants and increase surface energy.

[0037] S2. A flexible resin transition underlayer 511 is formed in the electrode lead-out area after surface pretreatment. Specifically, flexible epoxy resin, polyurethane resin, or acrylate resin is coated on the electrode lead-out area of ​​the metal electrode 4 and cured at low temperature to form the flexible resin transition underlayer 51. The curing temperature can be 50℃~120℃, and the curing time can be 10min~60min. For perovskite devices with low heat resistance, a low-temperature or UV-curable resin system is preferred.

[0038] S3. Deposit an intermediate porous stress-buffered silver layer 512 on the flexible resin transition substrate 511. Physical vapor deposition (PVD) is preferred, and sputtering deposition is even more preferred. During deposition, a combination of high pressure, low power, low bias, and low temperature is used to cause Ag atoms to collide multiple times during their flight, reducing the energy required to reach the substrate surface, thereby forming island-like growth, porous, or loose granular structures. Preferably, the deposition pressure is 1.0 Pa to 5.0 Pa, the deposition power is 20 W to 80 W, and the deposition temperature does not exceed 80 °C.

[0039] S4. Deposit a dense conductive silver layer 513 on the intermediate porous stress-buffered silver layer 512. Physical vapor deposition (PVD) is preferred, and sputtering deposition is even more preferred. During deposition, a combination of low gas pressure, high power, moderate bias, and moderate temperature is used to enable Ag atoms to acquire high surface migration energy, allowing them to fully diffuse and crystallize on the surface of the intermediate porous stress-buffered silver layer 512, forming a continuous silver film with high density and high conductivity. Preferably, the deposition gas pressure is 0.1 Pa to 0.8 Pa, the deposition power is 80 W to 200 W, and the deposition temperature is room temperature to 120 °C.

[0040] S5. A curved flexible conductive adhesive layer 6 is formed on the dense conductive silver layer 513. Specifically, a flexible conductive adhesive or nano-silver paste is applied to the dense conductive silver layer 513 using a dispensing device, with the application trajectory being curved. The curved shape includes S-shape, serpentine shape, wavy shape, arc shape, zigzag shape, or a combination thereof. In this embodiment, an S-shaped trajectory is preferred. The flexible conductive adhesive can be a silicone-based conductive adhesive, a flexible epoxy-based conductive adhesive, a polyurethane-based conductive adhesive, an acrylate-based conductive adhesive, or nano-silver paste.

[0041] S6. Apply the single-sided Cu conductive tape 7 to the curved flexible conductive adhesive layer 6, so that the single-sided Cu conductive tape 7 is electrically connected to the composite electrode body 5 through the curved flexible conductive adhesive layer 6. The application can be performed using partial pressing, rolling, or vacuum-assisted bonding. Preferably, the pressing pressure is 0.05 MPa to 0.5 MPa, and the pressing time is 5 s to 60 s.

[0042] In the thermal cycling resistant composite electrode prepared through the above steps, the flexible resin transition layer 511, the intermediate porous stress buffer silver layer 512, and the surface dense conductive silver layer 513 constitute a multi-gradient CTE transition structure from the flexible transition layer, the porous buffer layer to the dense conductive layer; the curved flexible conductive adhesive layer 6 further provides geometric deformation redundancy between the composite electrode body 5 and the single-sided Cu conductive tape 7. Thus, the electrode lead-out area is transformed from the traditional rigid connection method of "metal electrode—straight adhesive layer—Cu conductive tape" to a hierarchical connection method of "multilayer nano-metal composite electrode—curved flexible conductive adhesive layer—single-sided Cu conductive tape".

[0043] Example 2. Conductive adhesive composite layer type thermal cycling resistant composite electrode This embodiment provides a thermally resistant composite electrode that uses a conductive adhesive composite layer 52 as the composite electrode body 5.

[0044] like Figure 2 As shown, the conductive adhesive composite layer 52 includes a perovskite-side low-modulus flexible adhesive layer 521, a conductive skeleton intermediate layer 522, and an encapsulation-side buffer surface layer 523 arranged sequentially along the direction away from the perovskite power generation layer 3.

[0045] The perovskite-side low-modulus flexible adhesive layer 521 is disposed in the electrode lead-out area of ​​the metal electrode 4, and its material can be silicone-based, polyurethane-based, flexible epoxy-based, or acrylate-based adhesive material. This layer is directly close to the metal electrode 4 side of the perovskite component, and its low-modulus characteristics can improve the flexible adaptability with the layer side of the perovskite device.

[0046] The conductive framework intermediate layer 522 is disposed on the perovskite-side low-modulus flexible adhesive layer 521, and includes a conductive filler and a polymer matrix. The conductive filler includes silver particles, silver nanowires, silver flakes, copper particles, carbon nanotubes, graphene, or combinations thereof. Preferably, the conductive filler is a combination of silver flakes and silver nanowires to form a continuous conductive network while maintaining a certain degree of flexibility.

[0047] The encapsulation-side buffer layer 523 is disposed on the conductive skeleton intermediate layer 522. The encapsulation-side buffer layer 523 can be an epoxy resin layer, a polyurethane layer, a fluorosilicone resin layer, an acrylate resin layer, or a combination thereof. The encapsulation-side buffer layer 523 is located near the single-sided Cu conductive tape 7 or the external encapsulation side, and is used to form a buffer interface between the conductive skeleton intermediate layer 522 and the external connection structure.

[0048] The preparation method of this embodiment includes the following steps: S1. Perform surface pretreatment on the electrode lead-out area of ​​the metal electrode 4 of the perovskite photovoltaic module. The surface pretreatment includes solvent cleaning, ultraviolet ozone treatment, plasma activation, or a combination thereof.

[0049] S2. A perovskite-side low-modulus flexible adhesive layer 521 is formed in the electrode lead-out area of ​​the metal electrode 4. Specifically, a silicone-based, polyurethane-based, flexible epoxy-based, or acrylate-based adhesive material is coated on the electrode lead-out area and cured at low temperature or pre-cured to form the perovskite-side low-modulus flexible adhesive layer 521.

[0050] S3. A conductive framework intermediate layer 522 is formed on the perovskite-side low-modulus flexible adhesive layer 521. Specifically, a conductive paste containing silver particles, silver nanowires, silver flakes, copper particles, carbon nanotubes, graphene, or combinations thereof is coated or printed on the perovskite-side low-modulus flexible adhesive layer 81 and cured at low temperature to form the conductive framework intermediate layer 522.

[0051] S4. An encapsulation-side buffer layer 523 is formed on the conductive framework intermediate layer 522. Specifically, epoxy resin, polyurethane, fluorosilicone resin, acrylate resin, or a combination thereof are coated on the conductive framework intermediate layer 82 and cured to form the encapsulation-side buffer layer 523.

[0052] S5. A curved flexible conductive adhesive layer 6 is formed on the encapsulation-side buffer surface layer 523. Specifically, flexible conductive adhesive or nano-silver paste is formed on the encapsulation-side buffer surface layer 523 by dispensing, screen printing, inkjet printing, or scraping. The extension trajectory of the curved flexible conductive adhesive layer 6 is S-shaped, serpentine, wavy, arc-shaped, zigzag-shaped, or a combination thereof. Preferably, in this embodiment, the curved flexible conductive adhesive layer 6 has an S-shaped extension trajectory.

[0053] S6. The single-sided Cu conductive tape 7 is attached to the curved flexible conductive adhesive layer 6, so that the single-sided Cu conductive tape 7 is electrically connected to the conductive adhesive composite layer 8 through the curved flexible conductive adhesive layer 6.

[0054] In this embodiment, the perovskite-side low-modulus flexible adhesive layer 521, the conductive framework intermediate layer 522, and the encapsulation-side buffer surface layer 523 form a conductive adhesive composite layer 52 that integrates flexible bonding, conductive transmission, and encapsulation-side buffering. Compared to a single-layer flexible conductive adhesive, this three-layer sandwich structure can reduce the abrupt deformation of a single material layer under thermal cycling, allowing the interfacial shear stress to be gradually released between the layers.

[0055] Example 3. Design of Curved Flexible Conductive Adhesive Layer Trajectory This embodiment designs the trajectory of the curved flexible conductive adhesive layer 6 based on embodiment 1 or embodiment 2.

[0056] The curved flexible conductive adhesive layer 6 can be S-shaped, sinusoidal, serpentine, corrugated, arc-shaped, polygonal, or a combination thereof. For smaller electrode lead-out areas, a single S-shaped or arc-shaped trajectory is preferred; for longer electrode lead-out areas, a continuous serpentine or corrugated trajectory is preferred; for areas that need to balance spatial layout and conductive path length, a combination of S-shaped and polygonal trajectories can be used.

[0057] The linewidth of the curved flexible conductive adhesive layer 6 can be 50μm to 1000μm, preferably 100μm to 500μm; the curve pitch can be 100μm to 3000μm, preferably 300μm to 1500μm; and the thickness can be 5μm to 200μm, preferably 10μm to 100μm.

[0058] In one specific embodiment, the curved flexible conductive adhesive layer 6 adopts a sinusoidal dispensing trajectory with an amplitude of 1.2 mm and a period of 3 mm. This trajectory enables the interfacial load of the adhesive layer to be dispersed along multiple peaks and troughs, avoiding the formation of sharp corner stress concentrations at both ends of the straight adhesive layer.

[0059] Example 4: CTE testing of multilayer gradient composite electrodes To verify the gradient transition effect of the thermal expansion coefficient of the multilayer nano-metal composite electrode, the following comparative test was set up.

[0060] Comparative Example 1 uses a single-layer sintered nano-silver electrode. The Example Group uses the multilayer nano-metal composite electrode described in Example 1, which has a structure of a dense conductive silver layer 513 on the surface, a porous stress-buffered silver layer 512 in the middle, and a flexible resin transition bottom layer 511.

[0061] The test results are shown in Table 1.

[0062] Table 1 As shown in Table 1, compared with the single-layer sintered silver nanoelectrode, the equivalent overall CTE of the multilayer gradient composite silver nanoelectrode is closer to the perovskite active layer region. The difference between the CTE and the perovskite CTE decreases from 48.3 to 7.8, the maximum interfacial thermal stress decreases from 41.6 MPa to 10.3 MPa, and the stress concentration factor decreases from 5.14 to 1.51. This indicates that the flexible resin transition bottom layer 511, the intermediate porous stress buffer silver layer 512, and the surface dense conductive silver layer 513 can jointly form a CTE gradient transition structure.

[0063] Example 5: CTE test of conductive adhesive composite layer To verify the thermal cycling buffering effect of the conductive adhesive composite layer 52, the following comparative test was set up.

[0064] Comparative Example 2 uses a single-layer flexible conductive adhesive. The Example Group uses the conductive adhesive composite layer 52 described in Example 2, which has the structure of a perovskite-side low-modulus flexible adhesive layer 521, a conductive framework intermediate layer 522, and an encapsulation-side buffer surface layer 523.

[0065] The test results are shown in Table 2.

[0066] Table 2 As shown in Table 2, compared with the single-layer flexible conductive adhesive, the difference between the multilayer sandwich composite conductive adhesive electrode and the perovskite CTE decreased from 19.6 to 6.5, and the interfacial peak shear stress decreased from 33.8 MPa to 9.7 MPa. This indicates that the low-modulus flexible adhesive layer 521 on the perovskite side, the conductive skeleton intermediate layer 522, and the buffer surface layer 523 on the encapsulation side can release thermal cycling stress through interlayer micro-deformation.

[0067] Example 6: Comparison Experiment of Straight Line Dispensing and Curved Dispensing To verify the stress dispersion effect of the curved flexible conductive adhesive layer 6, a comparative experiment was set up to compare straight dispensing and curved dispensing.

[0068] The test conditions were as follows: flexible conductive silicone adhesive with a Shore A hardness of 22 and an elastic modulus of 0.8 MPa; cell thickness of 180 μm; and a thermal cycling simulation temperature range of -40℃ to 85℃. Sine curve dispensing was used, with an amplitude of 1.2 mm and a period of 3 mm.

[0069] The results of the finite element stress simulation are shown in Table 3.

[0070] Table 3 The results above show that curved dispensing can disperse the concentrated stress at both ends of straight dispensing to multiple peaks and troughs of the curved dispensing line, thereby reducing the maximum equivalent stress at the adhesive layer interface, the peak stress at the edge of the solar cell, and the stress concentration factor.

[0071] Further peel / tensile shear strength tests were conducted. The same perovskite solar cell and tin-plated solder strip were used for the test samples, and the amount of adhesive used and the curing parameters were kept consistent, with only the dispensing trajectory being changed.

[0072] Test results are shown in Table 4.

[0073] Table 4 As shown in Table 4, curved wave dispensing can increase the effective bonding perimeter and interfacial bonding area, and improve peel force and shear strength by buffering the lamination or thermal cycling load through the deformation of the flexible adhesive layer.

[0074] Example 7. Nano-silver paste curvilinear dispensing thermal cycling test This embodiment uses low-temperature sintering nano-silver paste to compare the thermal cycling shear strength of straight-dispensed nano-silver paste joints and curved S-shaped dispensed nano-silver paste joints.

[0075] The test conditions were: 1000 thermal cycles at -40℃ to 125℃.

[0076] Test results are shown in Table 5.

[0077] Table 5 The results show that the curved S-shaped dispensing nano-silver paste joint has higher initial room temperature shear strength and strength after 1000 thermal cycles than the straight dispensing nano-silver paste joint. Although the strength decay rate of the curved S-shaped dispensing joint is higher, its absolute shear strength after thermal cycling is still significantly higher than that of the straight dispensing joint, indicating that the geometric redundancy of the curved dispensing and the stress relaxation ability of the nano-silver sintered micropores have a synergistic effect.

[0078] Further mechanical load tests were conducted. Under simulated snow load of 5400 Pa, the local pressure at both ends of the straight nano-silver paste dispensing line was 11.7 MPa, and microcracks appeared at the edges of some cells. For the wavy nano-silver paste dispensing line, the load was evenly distributed across multiple segments, with the peak pressure decreasing to 4.3 MPa, and no microcracks were observed. Regarding the warpage after module lamination, the straight-line adhesive was 1.87 mm / m, while the wavy-line adhesive was 0.62 mm / m, a reduction of 66.8%.

[0079] The comparison of interface fracture modes shows that straight dispensing mainly manifests as interfacial peeling fracture, while curved dispensing mainly manifests as silver paste cohesive fracture. This indicates that the curved dispensing structure can improve the reliability of interfacial adhesion and transfer the failure location from the interface to the colloid body.

[0080] In summary, this invention, through the combined design of the composite electrode body 5, the curved flexible conductive adhesive layer 6, and the single-sided Cu conductive tape 7, constructs a multi-gradient CTE transition and curved deformation redundancy structure in the electrode lead-out region of the metal electrode 4 of the perovskite photovoltaic module, which can improve the interface stability and electrical connection reliability of the electrode lead-out region under space thermal cycling conditions.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, adjustments or substitutions can be made to the materials of each component, layer thickness, trajectory of the curved flexible conductive adhesive layer, bonding method of the single-sided Cu conductive tape, and the specific structure of the composite electrode body without departing from the concept of the present invention. All such adjustments or substitutions should be included within the scope of protection of the present invention.

Claims

1. A thermally resistant composite electrode for a space-use perovskite photovoltaic module, characterized in that, The heat-resistant composite electrode is used to be disposed in the electrode lead-out area of ​​the metal electrode of the perovskite photovoltaic module. The heat-resistant composite electrode includes a composite electrode body, a curved flexible conductive adhesive layer and a single-sided Cu conductive tape. The composite electrode body is disposed in the electrode lead-out area; The curved flexible conductive adhesive layer is disposed on the composite electrode body and extends in a curved shape along the surface of the composite electrode body; The single-sided Cu conductive tape is disposed on the curved flexible conductive adhesive layer and is electrically connected to the composite electrode body through the curved flexible conductive adhesive layer; The composite electrode body is a multilayer nano-metal composite electrode or a conductive adhesive composite layer.

2. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 1, characterized in that, The extension trajectory of the curved flexible conductive adhesive layer is S-shaped, serpentine, wavy, arc-shaped, zigzag-shaped, or a combination thereof.

3. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 1, characterized in that, The multilayer nano-metal composite electrode comprises a flexible resin transition layer, a porous stress-buffered silver layer in the middle, and a dense conductive silver layer on the surface, which are stacked sequentially along the direction away from the perovskite power generation layer.

4. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 3, characterized in that, The flexible resin transition substrate is a PI layer, a PET layer, a PEN layer, a PC layer, a flexible epoxy resin layer, a polyurethane resin layer, or an acrylate resin layer.

5. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 3, characterized in that, The intermediate porous stress-buffered silver layer is a porous silver layer or a porous composite metal layer with silver as the main component; the surface dense conductive silver layer is a dense silver layer or a dense composite conductive layer with silver as the main component.

6. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 3, characterized in that, The intermediate porous stress-buffered silver layer is in the form of islands, columns, loose granules, or a porous continuous network. The thickness of the intermediate porous stress-buffered silver layer is 50nm to 1000nm, and the thickness of the surface dense conductive silver layer is 100nm to 3000nm.

7. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 1, characterized in that, The conductive adhesive composite layer includes a perovskite-side low-modulus flexible adhesive layer, a conductive skeleton intermediate layer, and an encapsulation-side buffer surface layer, arranged sequentially along the direction away from the perovskite power generation layer.

8. The thermally resistant composite electrode for a space-use perovskite photovoltaic module according to claim 7, characterized in that, The perovskite-side low-modulus flexible adhesive layer is a silicone-based, polyurethane-based, flexible epoxy-based, or acrylate-based adhesive layer; the conductive framework intermediate layer includes silver particles, silver nanowires, silver flakes, copper particles, carbon nanotubes, graphene, or combinations thereof; the encapsulation-side buffer surface layer is an epoxy resin layer, a polyurethane layer, a fluorosilicone resin layer, an acrylate resin layer, or combinations thereof.

9. A method for preparing a thermally resistant composite electrode for a space-use perovskite photovoltaic module, characterized in that, Includes the following steps: S1. A composite electrode body is formed in the electrode lead-out area of ​​the metal electrode of the perovskite photovoltaic module; S2. A curved flexible conductive adhesive layer is formed on the composite electrode body; S3. Apply a single-sided Cu conductive tape to the curved flexible conductive adhesive layer, so that the single-sided Cu conductive tape is electrically connected to the composite electrode body through the curved flexible conductive adhesive layer to obtain a thermally resistant composite electrode.

10. The method for preparing the thermally resistant composite electrode of the space perovskite photovoltaic module according to claim 9, characterized in that, In step S1, when the composite electrode body is a multilayer nano-metal composite electrode, the following steps are included: S11. A flexible resin transition substrate is formed in the electrode lead-out area; S12. Deposit an intermediate porous stress-buffered silver layer on the flexible resin transition substrate; S13. Deposit a dense conductive silver layer on the surface of the intermediate porous stress buffer silver layer. The intermediate porous stress-buffered silver layer is formed by physical vapor deposition, with a deposition pressure of 1.0 Pa to 5.0 Pa, a deposition power of 20 W to 80 W, and a deposition temperature not exceeding 80 °C; the surface dense conductive silver layer is formed by physical vapor deposition, with a deposition pressure of 0.1 Pa to 0.8 Pa, a deposition power of 80 W to 200 W, and a deposition temperature of room temperature to 120 °C. When the composite electrode body is a conductive adhesive composite layer, step S1 includes the following steps: forming a perovskite-side low-modulus flexible adhesive layer, a conductive skeleton intermediate layer, and an encapsulation-side buffer surface layer sequentially in the electrode lead-out area.

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